Issue a warning if bindAttributeLocation() is used after shaders linked

Attribute locations must be bound before a shader program is linked
according to the GLSL specification.  Issue a warning to the user if
they do it in the wrong order, which should help to isolate hard
to find bugs much quicker.

Reviewed-by: trustme

1 files changed, 8 insertions, 3 deletions

diff --git a/src/opengl/qglshaderprogram.cpp b/src/opengl/qglshaderprogram.cpp
index dfa6c40..34114e4 100644
--- a/src/opengl/qglshaderprogram.cpp
+++ b/src/opengl/qglshaderprogram.cpp
@@ -1265,7 +1265,12 @@ GLuint QGLShaderProgram::programId() const
 */
 void QGLShaderProgram::bindAttributeLocation(const char *name, int location)
 {
-    glBindAttribLocation(d->programGuard.id(), location, name);
+    if (!d->linked) {
+        glBindAttribLocation(d->programGuard.id(), location, name);
+    } else {
+        qWarning() << "QGLShaderProgram::bindAttributeLocation(" << name
+                   << "): cannot bind after shader program is linked";
+    }
 }
 
 /*!
@@ -1280,7 +1285,7 @@ void QGLShaderProgram::bindAttributeLocation(const char *name, int location)
 */
 void QGLShaderProgram::bindAttributeLocation(const QByteArray& name, int location)
 {
-    glBindAttribLocation(d->programGuard.id(), location, name.constData());
+    bindAttributeLocation(name.constData(), location);
 }
 
 /*!
@@ -1295,7 +1300,7 @@ void QGLShaderProgram::bindAttributeLocation(const QByteArray& name, int locatio
 */
 void QGLShaderProgram::bindAttributeLocation(const QString& name, int location)
 {
-    glBindAttribLocation(d->programGuard.id(), location, name.toLatin1().constData());
+    bindAttributeLocation(name.toLatin1().constData(), location);
 }
 
 /*!